Oil Imperium (Black Gold in the US) is a business sim created and published in 1989 by reLINE Software for Atari ST, Commodore 64, DOS and Amiga.
The game was designed by a group of people that include P.

Elite is a famous space flight and trading sim created by David Braben and Ian Bell (with their company, Mr Micro), published by Acornsoft and Firebird, and released for several home computers starting from 1984.

Sid Meier's Railroad Tycoon (or, simply, Railroad Tycoon) is a trains management and business sim created by MPS Labs and released by Microprose in 1990 for MS-DOS and Amiga. In 1991 it was ported to Atari ST and Macintosh.

Red Baron was created by Damon Slye at Dynamix and published by Sierra Entertainment in 1990 for MS-DOS 5.0. Two years later it was ported to Amiga.
Red Baron is a flight simulator game set in World War I, on the western front.

EF2000 is a combat flight simulator developed by Digital Image Design and published by Ocean Software for PC in 1995.
The game, the sequel to TFX, puts the player in the cockpit of a Eurofighter Typhoon (also know as EF2000).